Balanced rear-axle drive



March l 1927. 1,619,051

A. H. AsPRoo'rl-l ET AL BA'LANCED REAR AXLE DRIVE Filed Sept. 4. 1923 4 Shets-Sheet 2 ATTORNEY."

Mwah 1,1927. v1,619,051

y A. H. ASPROOTH ET AL BALANCED REAR yAXLE DRIVE Filed sept. 4. 1923` 4 sheets-sheet s zal* 4'/ f3 37 30 MM 3,

Il. Z' i 40V/ @D n "l JNVENToRs f yATTORNEY L March l 1927.

. 1,619,051 A. H. ASPROOTH ET AL.

- BALANCED REAR AXLE DRIVE Filed Sept. 4. 1923 4 Sheets-Sheet 4 Patented Mar. l, 1927.A

y UNITED STATES PATENT oFFIcE.

AXEL HJ'. ASPROOTH, OE BALTIMORE, MARYLAND, AND ALFONSO M. LEONI, OF PHILADELPHIA, PENNSYLVANIA; SAID LEONI ASSIGNGR TO ELECTRO-MOTIVE DEVICES, INC., OE PHILADELPHIA, PENNSYLVANIA, A CORPORATION OF NEW JERSEY.

Application filed September a, 1923. "Serial No. 660,714.

The invention relates more particularlyV to 'motor carried driving'axles for automo- Y tive vehicles.

rlhe principal objects are to provide a rear axle drive whereof the elements will be fully balanced as to driving forces and will be wholly free of thrust loads; to provide a drive of the nature indicated whereof the motor and power transmission sets will be' supported in co-,axial alinement by a cio-axial arrangement and will be independent, as to the center lineV support afforded by this arrangement, of the jack shafts andV ground wheels; to provide a center line or co-axial arrangement of the nature indicated, embodying an electric motor supported through the medium of a hollow shaft in 'bearings whose use is restricted to the carriage of the motor; a first reduction gear set'directly driven by the motor; a differential driven by the firstreduction gear set, the differential and gear set constituting a unit that is supported in bearings wholly independent of the motor supporting bearings; and driving connections from the differential to the final drive units 0r second reduction gear sets,

one of said driving connections extending through the motor shaft; to provide a rigid axle casing consisting of a centrally disposed motor casing and mated gear casings, including jack shaft sleeve extensions, the gear casings having webs with hubformations to co-operate with the annular bearings; to provide a construction whereof such parts as require machining may be turned in contradistinction to milling and the like expensive finishing; to provide a complete driving axle embodying in its organization standard elements capable of ready application and removal without dismantling the entireaxle; and to provide spiders for the gear sets so constructed that they are universally applicable to different conditions and with different forms of connection.'

Ve are aware that it has heretofore been proposed to provide av driving axle whereinV a motor drives a co-axially supported differential, but in this case the differential drives two reduction gear sets of the single step EALANCED EEAE-AXLE DRIVE.

type and arranged inthe groundwheelshe o vshaft passing through the motor revolving vat motor speed, and the motor and differen-v tial Vforminga unit as regard'stheir supporting bearings, the power shafts which operate the speed reduction gears being designed to float, through their corresponding driving pinions, on the pit-ch lines of the gearing system. In another instance, thel motor drives a gear set, forming .a unit with the differential, that takes care of t-he total speed reduction required. Hence, the driv ing shaft extending through the motor shaft rotates at the wheel speed. The motor, gear set and differential are supported as a unit by the same set of bearings that otherwise would be necessary tov supportv the motor alone.

`Our invention,V as indicated at the outset, is distinguished from the prior art constructions noted` in that the motor through the medium of its hollow shaft is afforded an independent means of bearing support; the

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constitute a unit that issupported in bearingsV wholly independent of the motor sup- 7 porting bearings; the gear sets that take care of the final reduction are supported in bearings wholly independent of those en ployed with themotor and the first reduc tion-differential unit. hile the last nientioned gear sets are independent of the motor and first reduction-differential units, with respect to their supporting bearings., nevertheless they yare so located that inwardly they take the driving power from the .corresponding differential shafts, while they transmit this power, duly reduced as to speed, at theirouter ends by means of wheel shafts of standard construction. The wheel shafts, in effect, are within the confines of 4the axle `andare balanced at their inner ends drawings,- Y Figure 1 is a view principally 1n longitudinal section of a rear axle drive embodying features of our invention.

Fig. 2 is an enlarged sectional view of the first reduction gear set and differential unit.

Fig. 3 isa similar view of one of the second reduction gea-r sets.

Fig. 4 is an end view of the preferred spider construction; and

Fig. 5 is a section on line 5 5 of Fig. 4.

The conventionally illustrated motor is housed within a central casing 5 whereof the end plates 6 are provided with annular bearings 7 for the hollow motor shaft 8. The gear casings 9, which together with the motor casing form the complete axle casing, are bolted or otherwise removably and rigidly secured to the end plates 6, as at 10. The wall of the gear casings 9 are formed with comparatively large openings 9 to afford convenient access to the gearing.

The motor shaft 8 is provided, within one of the gear casings, with a motor pinion 11, which drives a first reduction gear set 12. This, by way of illustration, is represented by a planetary system of three planets 13, co-operating with the pinion 11 and with a fixed annular rack 14 formed or provided internally of the gear casing. The first reduction gear set drives a differential 15 of any approved type, the remote ends of the differential and of the gear set being centered as a unit by annular bearings 16 and 17, which it will be noted are independent of the motor supporting bearings 7. llhe bearing 16 is carried by the hub or shaft receiving portion 18 of a radial web 19 which may or may not be integral with the gear casing. A similar web construction 2O is present in the companion gear casing.

Operatively connected with the differential are two driving shafts 21 and 22, whereof the former drives the immediately adjacent second reduction gear set 23, and where- -of the shaft 22 extends through the hollowr shaft of the motor and drives the other second reduction gear set 24. It will be noted that accuracy of alinement of the driving shafts is preserved by their journals in the hub members 18 of the gear casing web formations.

The second reduction gear sets are shown by way of example as planetary systems, embodying four planets 25, which co-operate with driving pinions 26, 27, on the respective driving shafts and with fixed annular racks 28, 29 secured internally of the gear casing.

The end frames or spiders for the planets are centered by annular bearings 8O and 31, the former being disposed on the hub 18 and the latter being accommodated by the driv- Ving frame of the reduction set and by the inwardly directed terminal 32 of the gear casing proper. The jack or wheel shafts 33 are detachably secured with relation to the second reduction gear sets, in the manner indicated at 34. Their sleeves or casings 35 telescope the respective gear casings and are bolted or otherwise secured to the end plates of the motor casing. rlhey are additionally secured or directed webs 36 which are Vafforded a bearing on a shoulder 37 of the gear casing terminal.

As shown in Figs. 4 and 5, the planet carrying spiders are of such construction that they can be readily turned instead of being formed, as heretofore, by milling. Hence, they can readily be adapted'to meet standard conditions and requirements. In the preferred embodiment, they comprise confronting disc members 38 and 39 integrally joined, at their rims only, by .lug-like straps 40. The disc 39 is bored to tit the hub 4l of the tiange member 42, which, as show-n in Fig. 3, is splined to the jack shaft, and it may or may not have the annular shoulder 43, which, when present, seatsr on the rim 44 of the jack shaft flange member. The bore of the disc 38 is somewhat larger to accommodate the annular' bearing member and has an 4inner shoulder 45, which constitutes an abutment for said bearing member- The spiders have more than the required number of planet journal openings 46 in order that they may be standardized to meet any usual condition or type of connection.

Having described our invention, we claim y 1. A rear axle drive including a motor, a lirst reduction gear set, a Ahollow shaft connecting it with the motor, a differential driven by said gear-set and supported therewith, as a unit, independently of the motor support, second reduction. gear sets, one on each side of the motor, driving connections between the diderenti'al and second reduction gear sets, and an axle housing with web extensions in which said driving connections are journaled and which carry one of the bearings for the dierential and one of the bearings of the respective second reduction gear sets. Y I

2. A rear axle drive including amotor, a rst reduction gear set directly driven by the motor, a dierent-ial driven by said gear vset and supported with it, as a unit, independently of the motor support, second reduction gear K driving connections between the differential and second reduction gear sets, opposed annular bearings for each of the second `reduction gear sets, and an axle housing with web extensions in which said Vdriving connections are journaled and which carry one of the bearings for the differential and the corresponding inner bearing of the second reduction gear sets, the outer bearings of said sets functioning, in addition to supporting the load, to balance inwardlythe wheel shaft end reactions.

supported by inwardly l It) sets, one on each side of the motor,

3. The combination with a drive of the easy access to the gearing, and terminal Seetype recited, of a sectional axle honsingemtions telescoping the gear casings. bodying a motor caeing including individual In testimony whereof We have hereunto .15 bearings for the motor, Separate gear ees? signed our names. 5 ings each carrying its own load and having Webs and bearings for centering the gear` AXEL HJ. ASPROOTH. ing and having large openings affording .V l i ALFONSO'M. LEONI.

CERTlFlCAEE 0F CRRECTUN Pateii Ne. i,6i9,051. Granted Meieii i, i927, te

AXEL Hi ASPROGTH ET AL..

it is hereby eeiiiied that the above eumiiere paient was emneouey issued to Axel Hi. Aepreetii and Aiielise M. Leeei, seid Leeiii assigner ie Electre-Motive Devices, ine., ei Philadelphia, Pemisyivania, a eeiperatien 0i New Jeifsey, Whereas said Letters Patent should have been issued ie Eieere-Metive Deviees, hee.s of Philadelphia, Pennsylvanie e. eei'pereiieii of New lieisey, said eeiperetion being assignee 0f the entire interest in said ieveu'tien, as shew@v hy iziie ieeei'de ef as signmenis in this efiiee; and nei iie seid Letieie Fatemi: eiieuiii be Wiih this correction therein that ihe same may eeiieiei te the reeerii ei iiie eeee in the Patent Office,

Signed and sealed this Zih day 0i Aerii, A D, i922 M, J., Mooie, Seai. Acting Gemmieeienei ei Patents., 

